Portable Solar Generator. Start Up Project 16

7AWhat will do if you are in a place where AC is not available to power your gadgets ? You can carry this Portable Solar Generator to a Picnic spot where AC is not available. It lights a CFL to provide sufficient light and AC for charging Mobile Phone, Tablet etc and can even play a small CD player. Alternately you can use the unit in home during Power Outage days. It converts the 12 V DC from the battery to 220V AC to light the CFL. It has a bulb holder to fix the CFL and an AC outlet to tap AC for other purposes. It uses a simple 20 Watts CFL Driver board to converts DC to AC. The battery can be charged using a 12 V Solar panel or 12V DC Adapter. The battery used in this unit is 12V 3 Ah (3 Ampere Hour) rechargeable Lead acid battery which can power the CFL many hours.
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Solar Power Outlet. Start Up Project 4

17AWhy wasting electricity for charging USB devices including Mobile phone? Sun is there to give power for this. Install a Solar Power Outlet in your home to harvest solar power for charging all USB devices in day time. Its cost is only Rs.500 and you get unlimited day power for more than 25 years to charge all USB devices. The expensive part of the project is Solar Panel. A 12 Volt 5 watts Solar panel costs around Rs.400 because the current rate is around Rs.80 per watt. The remaining components costs only Rs.100. So by spending Rs.500 initially, you can charge all your USB devices at the expense of only 6 Paisa per day . The calculation is for 25 years (50,000 Paisa / 9000 days = 5.5 Paisa). So hurry up to make this project.
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Voltage Monitor for Solar Panel. Design Note 46

Here is a simple circuit to monitor the voltage level in Solar panels. Usually a volt meter test is done during the installation of solar panel and then after, the panel remains unattended. If the solar panel is not providing sufficient voltage for charging the battery, that will permanently destroy it. A 12 volt Solar panel gives maximum of 22 volts DC in bright sunlight, which drops to around 16 volts when the load is connected. So a voltage level around 16 volts is necessary for charging the 12 volt Lead Acid battery. But the voltage output from the solar panel may reduce due to the accumulation of dust on the panel and corrosion of terminal contacts. These remain unnoticed ,so only when the battery fails ,we note this. This simple circuit solves the problem. If the solar panel  gives above 15 volts with the battery connected, the LED remains off. When the voltage from solar panel drops below 15 volts, LED turns on to indicate low voltage. This usually happens when the sunlight is low, but if the LED remains on in bright sunlight also, it indicates low output from the solar panel. The circuit can also be used as Battery level monitor.
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Smart Solar Charger. Design Note 31

IMAGEYou can make a simple Current regulated Charger for your Solar Panel. It safely charges the 12 volt battery with a constant current of 540 Milli Amperes. It needs only a few components and can be hooked between the Solar panel and the battery. It also has an LED charge indicator and a revere polarity protection diode.
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How to Protect Solar Inverter Battery .Design Note 28

One of the main problems in Solar Inverter system is poor charging of Battery during rainy seasons and in cloudy days. The high current Tubular battery requires more than 1 Ampere current for proper charging. To solve this problem, I have designed a” Hybrid Solar charger” and the circuit was published in Electronics for You magazine September 2013 issue. So the charger has two sides. One side gets power from Solar panel and the other side from a Step-down transformer. If the voltage from Solar panel reduces below 9 volts, the charger shifts to AC mode and battery charges via the current from transformer.
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Simple Solar Power System. Design Note 18

Solar based power system is now becoming popular to save energy and money. It is easy to install a simple 100 Watts Solar lighting system for outdoor lighting. No need for constructing the circuits and all necessary units are readily available and anybody can install this. It runs on a 12 volt Car battery and no switching is needed. It turns on the outdoor lamps around 6 p.m and turns off at 6.a.m. The car battery can power the system for minimum 3 years so it is very cost effective. Another advantage is that, the outdoor lights will automatically turns on / off even if the inmates are not in home giving some security. Cost of the system is around Rs.5000 including battery.
The system requires the following:

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Simple Solar Charger. Design Trick 13

You can use this Solar charger to charge 12 volt Lead Acid or Tubular battery. It is voltage controlled and charge the battery when the output from Solar panel exceeds 15 volts in bright sunlight. The open circuit voltage of a 12 volt solar panel is around 20 volts in full light and the 12 volt battery requires around 14-15 volts for charging. The circuit also prevents the discharge of battery into the solar panel when the sunlight is low.
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